1. Field of the Invention
The present invention relates to a method of selecting a pattern to be measured, a pattern inspection method, a manufacturing method of a semiconductor device, a program, and a pattern inspection apparatus, for example, to selection and inspection of a fine pattern to be measured in a manufacturing process of a semiconductor device.
2. Related Background Art
In a manufacturing process of a semiconductor device a scanning electron microscope apparatus, for example, a type called a critical dimension scanning electron microscope (CD-SEM) is used to inspect a dimension of a fine pattern. Moreover, an alignment deviation error of a pattern between layers is measured by an alignment deviation inspection apparatus.
Conventionally, a method of selecting a pattern to be measured depends heavily on a sequence of preparation of measurement schedule of a measurement device. In the method, several wafers to be measured are first selected from one lot, a semiconductor chip to be measured is then selected with respect to these wafers, and a measurement portion in the selected chip is defined. Thereafter, a dimension or alignment deviation is measured in the same measurement portion with respect to all the wafers to be measured and all the chips to be measured. As a result, the number of wafers or chips constituting the measurement objects, and the total number of measurement portions in the chip are obtained by integration of these numbers. Therefore, when the wafer number, chip number, and in-chip measurement portions are simultaneously increased, a measurement cost exponentially increases.
As taught by a design of experiment method, this sampling strategy corresponds to a sampling strategy in which all alternate functions among factors such as fluctuations between the wafers and between the chips, and fluctuations in the chip are handled.
However, in actual, it is difficult to handle high-order alternate functions between the factors. Conversely, there has never been provided a factorial design method of performing measurement in which only the alternate functions to be handled are focused. Accordingly, there has never been provided a method of analyzing the fluctuations for each factor from measurement results obtained by the arrangement. Furthermore, in performing such a factorial design, it would have been remarkably difficult to prepare a measurement recipe in the above-described conventional measurement schedule preparation method.